Mature T/NK-cell lymphomas (C84) ICD-10-CM
The C84 code range covers mature t/nk-cell lymphomas with 98 ICD-10-CM diagnosis codes. 89 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- personal history of non-Hodgkin lymphoma Z85.72
Codes in the C84 Range 98 codes · 89 billable
- C84 Mature T/NK-cell lymphomasNon-billable
- C84.0 Mycosis fungoidesNon-billable
- C84.00 Mycosis fungoides, unspecified site
- C84.01 Mycosis fungoides, lymph nodes of head, face, and neck
- C84.02 Mycosis fungoides, intrathoracic lymph nodes
- C84.03 Mycosis fungoides, intra-abdominal lymph nodes
- C84.04 Mycosis fungoides, lymph nodes of axilla and upper limb
- C84.05 Mycosis fungoides, lymph nodes of inguinal region and lower limb
- C84.06 Mycosis fungoides, intrapelvic lymph nodes
- C84.07 Mycosis fungoides, spleen
- C84.08 Mycosis fungoides, lymph nodes of multiple sites
- C84.09 Mycosis fungoides, extranodal and solid organ sites
- C84.0A Mycosis fungoides, in remission
- C84.1 Sezary diseaseNon-billable
- C84.10 Sezary disease, unspecified site
- C84.11 Sezary disease, lymph nodes of head, face, and neck
- C84.12 Sezary disease, intrathoracic lymph nodes
- C84.13 Sezary disease, intra-abdominal lymph nodes
- C84.14 Sezary disease, lymph nodes of axilla and upper limb
- C84.15 Sezary disease, lymph nodes of inguinal region and lower limb
- C84.16 Sezary disease, intrapelvic lymph nodes
- C84.17 Sezary disease, spleen
- C84.18 Sezary disease, lymph nodes of multiple sites
- C84.19 Sezary disease, extranodal and solid organ sites
- C84.1A Sezary disease, in remission
- C84.4 Peripheral T-cell lymphoma, not elsewhere classifiedNon-billable
- C84.40 Peripheral T-cell lymphoma, not elsewhere classified, unspecified site
- C84.41 Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of head, face, and neck
- C84.42 Peripheral T-cell lymphoma, not elsewhere classified, intrathoracic lymph nodes
- C84.43 Peripheral T-cell lymphoma, not elsewhere classified, intra-abdominal lymph nodes
- C84.44 Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of axilla and upper limb
- C84.45 Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of inguinal region and lower limb
- C84.46 Peripheral T-cell lymphoma, not elsewhere classified, intrapelvic lymph nodes
- C84.47 Peripheral T-cell lymphoma, not elsewhere classified, spleen
- C84.48 Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of multiple sites
- C84.49 Peripheral T-cell lymphoma, not elsewhere classified, extranodal and solid organ sites
- C84.4A Peripheral T-cell lymphoma, not elsewhere classified, in remission
- C84.6 Anaplastic large cell lymphoma, ALK-positiveNon-billable
- C84.60 Anaplastic large cell lymphoma, ALK-positive, unspecified site
- C84.61 Anaplastic large cell lymphoma, ALK-positive, lymph nodes of head, face, and neck
- C84.62 Anaplastic large cell lymphoma, ALK-positive, intrathoracic lymph nodes
- C84.63 Anaplastic large cell lymphoma, ALK-positive, intra-abdominal lymph nodes
- C84.64 Anaplastic large cell lymphoma, ALK-positive, lymph nodes of axilla and upper limb
- C84.65 Anaplastic large cell lymphoma, ALK-positive, lymph nodes of inguinal region and lower limb
- C84.66 Anaplastic large cell lymphoma, ALK-positive, intrapelvic lymph nodes
- C84.67 Anaplastic large cell lymphoma, ALK-positive, spleen
- C84.68 Anaplastic large cell lymphoma, ALK-positive, lymph nodes of multiple sites
- C84.69 Anaplastic large cell lymphoma, ALK-positive, extranodal and solid organ sites
- C84.6A Anaplastic large cell lymphoma, ALK-positive, in remission
- C84.7 Anaplastic large cell lymphoma, ALK-negativeNon-billable
- C84.70 Anaplastic large cell lymphoma, ALK-negative, unspecified site
- C84.71 Anaplastic large cell lymphoma, ALK-negative, lymph nodes of head, face, and neck
- C84.72 Anaplastic large cell lymphoma, ALK-negative, intrathoracic lymph nodes
- C84.73 Anaplastic large cell lymphoma, ALK-negative, intra-abdominal lymph nodes
- C84.74 Anaplastic large cell lymphoma, ALK-negative, lymph nodes of axilla and upper limb
- C84.75 Anaplastic large cell lymphoma, ALK-negative, lymph nodes of inguinal region and lower limb
- C84.76 Anaplastic large cell lymphoma, ALK-negative, intrapelvic lymph nodes
- C84.77 Anaplastic large cell lymphoma, ALK-negative, spleen
- C84.78 Anaplastic large cell lymphoma, ALK-negative, lymph nodes of multiple sites
- C84.79 Anaplastic large cell lymphoma, ALK-negative, extranodal and solid organ sites
- C84.7A Anaplastic large cell lymphoma, ALK-negative, breast
- C84.7B Anaplastic large cell lymphoma, ALK-negative, in remission
- C84.9 Mature T/NK-cell lymphomas, unspecifiedNon-billable
- C84.90 Mature T/NK-cell lymphomas, unspecified, unspecified site
- C84.91 Mature T/NK-cell lymphomas, unspecified, lymph nodes of head, face, and neck
- C84.92 Mature T/NK-cell lymphomas, unspecified, intrathoracic lymph nodes
- C84.93 Mature T/NK-cell lymphomas, unspecified, intra-abdominal lymph nodes
- C84.94 Mature T/NK-cell lymphomas, unspecified, lymph nodes of axilla and upper limb
- C84.95 Mature T/NK-cell lymphomas, unspecified, lymph nodes of inguinal region and lower limb
- C84.96 Mature T/NK-cell lymphomas, unspecified, intrapelvic lymph nodes
- C84.97 Mature T/NK-cell lymphomas, unspecified, spleen
- C84.98 Mature T/NK-cell lymphomas, unspecified, lymph nodes of multiple sites
- C84.99 Mature T/NK-cell lymphomas, unspecified, extranodal and solid organ sites
- C84.9A Mature T/NK-cell lymphomas, unspecified, in remission
- C84.A Cutaneous T-cell lymphoma, unspecifiedNon-billable
- C84.A0 Cutaneous T-cell lymphoma, unspecified, unspecified site
- C84.A1 Cutaneous T-cell lymphoma, unspecified lymph nodes of head, face, and neck
- C84.A2 Cutaneous T-cell lymphoma, unspecified, intrathoracic lymph nodes
- C84.A3 Cutaneous T-cell lymphoma, unspecified, intra-abdominal lymph nodes
- C84.A4 Cutaneous T-cell lymphoma, unspecified, lymph nodes of axilla and upper limb
- C84.A5 Cutaneous T-cell lymphoma, unspecified, lymph nodes of inguinal region and lower limb
- C84.A6 Cutaneous T-cell lymphoma, unspecified, intrapelvic lymph nodes
- C84.A7 Cutaneous T-cell lymphoma, unspecified, spleen
- C84.A8 Cutaneous T-cell lymphoma, unspecified, lymph nodes of multiple sites
- C84.A9 Cutaneous T-cell lymphoma, unspecified, extranodal and solid organ sites
- C84.AA Cutaneous T-cell lymphoma, unspecified, in remission
- C84.Z Other mature T/NK-cell lymphomasNon-billable
- C84.Z0 Other mature T/NK-cell lymphomas, unspecified site
- C84.Z1 Other mature T/NK-cell lymphomas, lymph nodes of head, face, and neck
- C84.Z2 Other mature T/NK-cell lymphomas, intrathoracic lymph nodes
- C84.Z3 Other mature T/NK-cell lymphomas, intra-abdominal lymph nodes
- C84.Z4 Other mature T/NK-cell lymphomas, lymph nodes of axilla and upper limb
- C84.Z5 Other mature T/NK-cell lymphomas, lymph nodes of inguinal region and lower limb
- C84.Z6 Other mature T/NK-cell lymphomas, intrapelvic lymph nodes
- C84.Z7 Other mature T/NK-cell lymphomas, spleen
- C84.Z8 Other mature T/NK-cell lymphomas, lymph nodes of multiple sites
- C84.Z9 Other mature T/NK-cell lymphomas, extranodal and solid organ sites
- C84.ZA Other mature T/NK-cell lymphomas, in remission
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the C84 range.
Lymph Nodes
They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.
Mycosis Fungoides
A chronic, malignant T-cell lymphoma of the skin. In the late stages, the LYMPH NODES and viscera are affected.
Pagetoid Reticulosis
A distinct variant of mycosis fungoides characterized by the presence of localized patches or plaques with an intraepidermal proliferation of neoplastic cells.
About the C84 Code Range
ICD-10 code C84 is used to classify mature T-cell and natural killer (NK) cell lymphomas, a group of rare cancers affecting lymphatic cells. These codes specify various types and anatomic sites of these lymphomas, including subtypes like Mycosis fungoides and Sezary disease.
This section helps medical coders identify precise diagnoses such as Mycosis fungoides (C84.0), a type of cutaneous T-cell lymphoma also known by synonyms like patch/plaque stage mycosis fungoides and classic mycosis fungoides. The codes differentiate involvement by specific sites, including lymph nodes of the head, intrathoracic lymph nodes, spleen, and extranodal locations. Sezary disease (C84.1), synonymous with Sézary's disease, is another important subtype coded here. Peripheral T-cell lymphoma not elsewhere classified (C84.4) and anaplastic large cell lymphomas, both ALK-positive (C84.6) and ALK-negative (C84.7), are also included. Detailed subcodes further specify affected sites, enabling accurate documentation for treatment and research.
The range covers conditions often labeled in clinical practice as Non-Hodgkin lymphoma variants and supports coding for remission states. For example, the ICD-10 code for mycosis fungoides assists in correctly recording diagnosis when clinicians use its many clinical synonyms. Overall, the C84 series ensures thorough classification of mature T/NK-cell lymphoma diseases by type and location.
Questions About This Page
How many billable codes are in the C84 range?
Of the 98 codes in this range, 89 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the C84 range classify?
The range classifies mature t/nk-cell lymphomas. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
